Time-controlled device.



W. HIGREENLEAFM TIME CONTROLLEDDEVIVCE. APPLICATION FILED NOV. 18, 191 5.

Patented Dec, 5, 1916.

' l'hvsnfor Fig. 3, looking UNITED STATES PATENT or r'ion.

WILLIAM H. GREENLEAF, OF HARTFORD, CONNECTICUT.

TIME-CONTROI1LED DEVICE.

Specification of Letters Patent.

Patented Dec. 5, 1916.

Application filed November 18, 1915. Serial No. 62,210.

' is a specification.

This invention relates to time-controlled devices.

While the lmprovements can with advantage be incorporated in time-controlled devices of various types, they are shown embodied in a secondary clock as distinguished from a master or primary clock. In certain types of self-winding clocks as they are known, the main arbor has associated with it a ratchet wheel operated intermittently by a pawl. It is a feature of the utmost importance, especially when accuracy is of such a vital consideration, that abnormal movement of this ratchet wheel should be prevented as far as possible.

It is one of the primary objects of the present invention to provide a simple construction wherein such abnormal movement of the ratchet wheel is properly and efli-.

ciently prevented.

Inthe drawings accompanying and forming part of the present -specification I have shown in detail one convenient form of embodiment of the invention which I will set forth fully in the following description. I do not restrict myself to this particular disclosure; I may depart therefrom in several respects within the scope of the invention defined by the claims following said description. I

Iteferring to said drawings: Figure 1 is a rear'view of a clock involving the invention. Fig. 2 is a similar view with the magnet removed. Fig. 3 is a view practically like Fig. 2 on a larger scale, with part of the armature broken away. F g. 1 is a horizontal section on the line H of in the direction of the arrow, the magnet being represented by dotted lines.

Like characters refer to like parts throughout the several views.

As already noted while my invention is susceptible of incorporation in time-controlled devices of various kinds, it is illustrated as incorporated in a secondaryclock comprising the late 2 (shown as a disk) forward of whic is mounted the dial 3 and in front of which dial are the hands l and o, the minute hand 5 being fastened to the arbor (3 extending through the plate 2, the

one to twelve train of gear 7 being interposed between the arbor (3 andthe sleeve 8 loose on said arbor and with which the hourhand i is rigid. The plate 2 has a cavity 9 to receive the said train of gears.

The foregoing. is a concise description of a secondary clock.

Associated with the arbor 6 in some suitable manner, is means by which said arbor is intermittently turned, said arbor being given an advance movement each minute and being under the control of a primary or master clock not shown. The means for effecting the intermittent action of the arbor (3 whether this action be each minute or otherwise. comprises as represented an electromagnet as 10 adapted to be energized at the requisite intervals, through the initial agency of the master clock and battery and other connections all of which, however, are not shown as the invention does not concern the same. Part of the wire connections 11 and 12 to the magnet 10, however, are shown in Fig. 1. The magnet 10 is fastened to the bracket 13 shown as being of angular or L-form, said magnet being attached by riveting or otherwise to what is shown as the horizontal branch of the bracket, said horizontal arm constituting the so-called heel iron of the magnet. The bracket is provided with flanges 1i and 15 which may be also fastened by riveting to the plate 3. The armature 16 for the magnet is shown pivoted to the upper end of the vertical branch of the bracket 13 and as having near its center of oscillation the downward extension 17 to which one end of a pull spring as 18 (constituting a\ suitable motor) is connected, the other end of the spring being connected with a tension-regulating screw 19 supported by the upward projection 20 of the horizontal branch of the bracket 13. Pivoted to the armature extension 17 is the pawl21 normally held in operative relation by the spring 22 acting thereagainst. This pawl coacts with the ratchet wheel 23 fastened in some suitable way to the arbor 6. As illustrated the ratchet wheel 23 has sixty teet I It will be assumed that the master clock through means associated therewith has closed the circuit including the magnet 10. The magnet is, therefore, energized, and as tension 17 being moved toward the left in Fig. 3, thereby moving the point or tooth of the pawl 21 out of one tooth space where it abuts against a tooth in front of .it and opposite a second tooth a space behind the other at which time the pawl is caused to enter the second tooth space by the power oi the spring 22 so that the point. of the pawl can engage the base of a second tooth. At about the time the pawl engages the second tooth the magnet is deenergized by the breaking of its circuit through the agency of the primary clock, so that the spring 18, put under tension by the outward movement of the extension 17, can pull said extension inward and cause the pawl 21 to move the ratchet wheel 23 one step or a distance equaling the length of one tooth of the ratchet wheel. It will, therefore, be clear that when the armature 16 is attracted or caused to advance, it acts through the intermediate parts to stretch or tension the spring 18 or render said spring efiective to draw back the pawl 21, whereas when said magnet is deenergized the spring will impart a working stroke to the extension 17 and therefore a working movement to the pawl 21 and at the same time cause the retraction of the armature 16.

The means for preventing abnormal movement of the ratchet wheel 23 comprises the detent or dog 24: shown as pivoted between its ends to the carrier25. This carrier 25 as illustrated, is in the form of a plate pivoted at one end as at 26 to the plate 2 and having near the other an arcuate slot 27 to receive the holding down screw 28 tapped into the plate 2. The slot 27 is concentric with the center of motion of the plate 25. From this it will be clear that said plate 25 can be adjusted (on the loosening of the screw 28) to bring the point of the detent 2% in accurate relation with the ratchet wheel 23 after which said screw is set. Connected with the short arm of the pivoted de- -tent 24 and with the plate 25 is a pull spring 29 which exerts a constant tendency to move the point or tooth of said detent into engagement with the toothed periphery of the ratchet wheel 23. In the construction shown the tooth of the detent is at the inner end of the long or angular arm of said detent.

I do not rely on the power of the spring v29 to maintain the detent 21 in restraining or braking relation with the ratchet wheel 23, as means of a, more positive nature have been provided for this purpose. The armature 16 serves satisfactorily in this latter connection. It will be seen that said armature is provided near the free end thereof with a lug 30. This lug is cooperative with the tail of the detent 24, being adapted to engage the inner surface of the short arm of sand detent, when the armature is practhus causing the stud or no mess tically in its retracted position. When, however, the armature is attracted by its magnet 10 the lug 30 will be moved from the full line position shown in Fig. 3 to the dotted line position in 'said view to wholly free the detent from the restraining influence of the armature at which time the detent will exercise no undue pressure against the ratchet wheel 23 to thus permit free movement of said ratchet wheel in the manner explained, by the pawl 21.

The action is as follows: The armature 16 is shown as being in its retracted position in Figs. 1, 2 and 3, the lug or stud 30 at this time being against the tail of the detent 24 so that the detent is forced firmly against the ratchet wheel through the initial efiect of the spring 18 under some but not maximum tension. It will be assumed that the magnet is energized. When it is the armature is attracted, the pawl 21 in the manner set forth being drawn back out of engagement with the tooth it is against and being caused to engage the tooth immediately back of said other tooth, this last mentioned action occurring practically when the armature 16 hascompleted its advance movement. As'tlie armature advances the lug 30 is moved out of engagement with the detent 24 to virtually the dotted line position in Fig. 3 at which point the armature will have completed its advancing movement, the pawl 21 at this time being back of said second, tooth mentioned.

under maximum tension can pull the extension 17 inward and at the same time retract the armature, the motion of the armature and its extension being sutiicient to efi'ect the feed of the ratchet wheel 23 a distance equal to one tooth of the ratchet. As the ratchet is thus turned by the pawl 21 the tooth of the ratchet wheel engaged by the point or tooth of the detent 24. causes the outward swing of the long arm of the detent so that the detent can pass behind a second tooth, this particular action occurring the instant the one step feed of the ratchet wheel is concluded. As the ratchet is fed forward the armature 16 is being re When the magnet 10 is deenergized, the spring 18 then tracted at approximately the same velocity lug 30 to move from the dotted line position to the full line position in F ig., 3, the stud suddenly striking the tail of the detent when the retractive movement of the armature is about completed and the forward feed of one step of the ratchet wheel concluded. The result of the stud 30 imparting th accelerated blow or pressure to the tail of the detent will be to cause the point or active end of said detent to bear solidly and firmly against the toothed periphery of the ratchet wheel 23 to an extent sutiicient to. positively prevent overthrow of the ratchet wheel two teeth which is a feature of the utmost importance. Naturally the thrust of the armature against the detent is ample to prevent reaction or backward. movement of the ratchet wheel. As the stud or lug 30 strikes thefdetentxZA, when the armature 16 is in its outward' or retracted position no stop other 'than the detent, is required to arrest the motion of 'the armature when in this par ticular position. It will'be perceived that the detent 24 ismoved suddenly against the ratchet wheel 23 practically at the concluthe, pawl 21 so that it will not be possible to sion of the end of an intermittent feed of advance the ratchet two teeth. As a matter of fact .in a large majority of cases the feed is just one tooth. Should it'be more than one tooth but less than two, the'point or beveled end of the detent by engaging the incline of a ratchet tooth between the base and crown thereof will ride down theincline of said particular tooth and with a camming action against the same return the ratchet wheel to a position Where the pawl will abut against thebase of a tooth back of which it may be.

That I- claim is: 1. The combination of a ratchet wheel, a pawl for feeding the ratchet wheel, a detent cooperative withthe ratchet wheel,

a magnet and its armature, and a spring connected with the armature, the armature when attracted by the magnet serving to tension the spring and the spring when the magnet is .denergized serving to impart a feed movement to the pawl and to retract the armature, the armature on its retractive movement engaging the detent to cause said detent to stop the motion of the ratchet wheel.

2. The combination of a ratchet wheel,

pawl for feeding the ratchet wheel, a detent cooperative with the ratchet wheel, a magnet and its armature, and a spring connected with the armature, the armature when attracted by the magnet serving to tension the spring and the spring when the magnet is deenergized serving to impart a feed movement to the pawl and to retract the armature, the armature on its retractive movementenga'gingthe detent to cause said de-.

tent to stop the motion of the ratchet wheel and thedetent' constituting a stop to limit theretractive movement of the armature. 3. The combination of an arbor, a ratchet wheel connected with the arbor, a minute handrigid with the arbor, a second hand looseon the arbor, a. train of gears between the two hands, a pawl 'forfeeding the ratchet wheel, a detent cooperative with the ratchet wheel,and automatic means for imparting pressure to the detent at about the completion of the feed of the pawl and in a direction to cause said detent to stop the motion of the ratchet wheel.

4:. The combination of a ratchet wheel, a

pawl for feeding the ratchet wheel, a detent ratchet wheel, a detent coiiperative with the ratchet wheel, and automatically active means, movable with the pawl, for inparting pressure to the detent at approximately the conclusion of each feed of the pawl, in adirection to cause the detent to stop the mo tion of the ratchet wheel.

In testimony whereof I afiix my signature in presence of two witnesses;

WILLIAM H. GREENLEAE.

Witnesses:

, L. L. MARKEL,

HEATH SUTHERLAND. 

